Counterpoised detachable tool head



April 3U, 1935. L. L. SCHAUER Er AL COUNTERPOISED DETACHABLE TOOL HEAD Filed Dec. 18, 1931 5 Sheets-Sheet 1 5140014 5014 Am MM Qbtozmew) April 39, 1935. L. SCHAUER ET AL COUNTERPOISED DETACHABLE TOOL HEAD 5 Shets-Sheet 2 Filed Dec. 18, 1931 avwemtou j y mac %41%4 M17- April 1935- L. SCHAUER El AL COUNTERPOISED DETACHABLE TOOL HEAD Filed Dec. 18, 1931 3 Sheets-Sheet 3 Patented pr. 3%, l

UQTERIPOISED DETACHLIE 'lliUWlL HEW Application December 118, 1931, Serial No. 581,906

13 Glaims.

The spindles of radial drills, together with their surrounding sleeves, and the tools carried thereby, are of great weight and, therefore, to be rendered easy of manipulation, must be counterbalanced. Such counter-balancing heretofore has been effected in one of two ways, to wit: either by the employment of a spiral spring counter-balance connected with the spindle sleeve, or by the use of a counter-weight connected with the sleeve by a flexible connector passed over a suitable pulley.

The weight type of counter-balance has its advantages in that it is readily adjustable to compensate for variations in the combined weight of the spindle, sleeve and tool due to the removal of one tool and the replacement thereof by a tool or other element of materially different weight. This compensation is effected by increasing or decreasing the weight of the counter-weight by adding to or taking therefrom as may be required. This type of counter-balance has, however, one or more decided disadvantages. First, it materially increases the load required to be carried by the radial arm, the disadvantages of which are wellrecognized by radial drill manufacturers and users, and which load the manufacturers have long endeavored to lessen. Second, because of the little space available within the drill head, and also in order to have the counter-weight accessible for variations, the weight is commonly located outside the head which detracts from the appearance of the machine.

'Ihe spring counter-balances have certain advantages over the counter-weights in that they do not add any substantial weight to the drillhead and, therefore, do not increase the load carried by the arm. Also they may be embodied wholly within the drill-head and, therefore, are not unsightly, as are the counter-weights. The spring counter-balances, however, also have their disadvantages. These devices admit of a certain amount of adjustment and, therefore, are capable Olf compensating for relatively small variations in load, such, for example, as is caused by the attachment of various weight tools to the tool spindle. They are, however, not capable of material adjustment such as would be required should the weight of the spindle sleeve, and the parts carried thereby be greatly increased, such for example, as by the application thereto of a multiple tool head which frequently weighs as much as 300 pounds.

This invention has for an object to provide improved means for detachably supporting a rel- (iCl. 7728) may be rotated and translated by the main tool spindle, and to combine therewith, in a unitary structure, an improved spring counter-balancing means for compensating for the weight of said auxiliary tool head.

Another object of the invention is to provide an improved self-counter-balancing multiple tool head for radial drills, so constructed and arranged that the head is supported and guided wholly independently of the usual tool spindle, the translation of the spindle, however, being utilized to eifect translation of the multiple tool head and the rotation of the spindle being transmitted to the auxiliary tool spindles carried by the tool head.

Still another object is to provide, in a selfcounter-balancing drill head, means for varying the effect of the counter-balancing device, or devices, thereby to compensate for the difierence in weight of various tools selectively attached thereto.

Other objects and advantages will be in part indicated in the following description and in part rendered apparent therefrom in connection with the annexed drawings.

To enable others skilled in the art so fully to apprehend the underlying features hereof that they may embody the same in the various ways contemplated by this invention, drawings depicting a preferred typical construction have been annexed as a part of this disclosure and, in such drawings, like characters of reference denote corresponding parts throughout all the views, of which:'

Figure 1 is a side elevation of a radial drill embodying the present invention. Fig. 2 is an enlarged side elevation, partly in section, of a preferred form of our improved multiple spindle head with the support and counter-balancing means therefor, showing it attached to the lower portion of a drill head. Fig. 3 is a sectional view substantially on the line 33 of Fig. 2. Fig. 4 is a view similar to Fig. 2 but showing a modified form. Fig. 5 is a sectional View substantially on the line 5-5 of Fig. 4.

Referringmore specifically to the drawingsthe invention is disclosed as embodied in a radial drill comprising a base B, column C, radial arm A and a main tool head H translatably mounted on the radial arm. While this invention advantageously may be embodied in radial drills it is to be understood that it is in nowise limited to that type of drilling machine, nor even to drilling machines generally.

The invention is shown in its preferred form in Figs. 1, 2 and 3, in which the tool head H is shown as provided with the conventional translatable sleeve L and a tool spindle S rotatably journaled in the sleeve. The spindle is adapted to be rotated, and the sleeve, with the spindle journaled therein, to be translated by mechanism within the tool head. Inasmuch as the rotating and translating mechanisms are conventional and formno part of the present invention detailed illustration and description thereof is deemed unnecessary for this disclosure.

As hereinbefore stated this invention relates primarily to the provision of a unitary structure comprising a multiple spindle head and means independent of the spindle sleeve for counterbalancing the head, said unitary structure being adapted to be removably secured to the main tool head. Referring particularly to Figs. 2 and 3, the preferred construction comprises a supporting member, or frame, I having a cylindrical portion 2 surrounding a hub h projecting downwardly from the head H, and three radially disposed legs 3. This support is fitted to the lower end of the drill head and is adapted to be secured thereto by any suitable means. Preferably this is effected by screwing into the tool head threaded bolts 4, the free ends of which extend through apertures in the frame I and receive nuts 5. Each of the legs 3 has secured to it a depending guide-bar 6 upon which is slidingly fitted an auxiliary tool head X having a plurality of auxiliary tool spindles I journaled therein. Within this auxiliary head is jcurnaled an auxiliary drive spindle 8 having a tapered shank 9 adapted to fit within the usual tapered bore in the main spindle S, to be driven thereby. Each of the auxiliary'spindles I is driven from the drive spindle 8 by means of a gear train designated generally as a: in a manner common to multiple spindle heads.

The auxiliary head H is formed with three tubular portions Ill each provided with a bushing II slidingly fitted to one of the guide bars 6. Thus it will be seen that the auxiliary head is supported and guided independently of the main spindle S but is free tobe moved downwardly by the downward movement of the latter.

This invention also provides improved means carried by and removable-with the frame I for a force tending to lift the auxiliary tool head.

By reason of the adjustment of the nuts H on the rods 8 the tension of the springs I 2 may be varied, thereby to compensate for different loads due to interchange of tools in the spindles I.

From the foregoing it will be perceived that the auxiliary head and its supporting frame readily may beattached to or removed from the main head of a machine tool as a complete unit, which unit also carries its own adiustable counter-balancing means.

Figs. '4 and 5 illustrate a modified form of the invention. This form differs from that previously described in that the auxiliary head X is supported upon and guided wholly by the spindle sleeve L. In this form the auxiliary head is formed with central tubular extension I! which surrounds the lower end of the sleeve L and is secured thereto by screws I 6. The auxiliary spindles 'l' are driven from the main spindles as described iii connection with Fig.2. A member I1 is removably secured to the lower end of the head H by any suitable means, such, for example, as by bolts I8 passing through apertures formed in the legs I8 thereof and threaded into the main head. The member I! is formed with a downwardly ex tending tubular portion I'I' which surrounds the portion I! of the auxiliary head and to which the portion I5 is keyed as shown at I9. A counter-balancing means similar to that hereinbefore described also is provided. This means comprises a rod 20 threaded into each of the legs I8 of the member I I and a coil spring 2I surrounding each of said rods. Each rod is also surrounded by a tubular member 22 secured to the auxiliary head, said members each forming a housing for one of the springs 2I. The upper end of each spring abuts against a wall'22 provided by the member 22 and the lower end of each spring is seated upon a nut 22 adjustably threaded upon the rod 20. It is to be noted that in this form of the invention the auxiliary head is guided wholly by the spindle sleeve L; the tubular members 22 loosely surrounding the rods 20. From the foregoing it will be apparent that we have provided, as a unitary structure, a selfcounter-balancing auxiliarymultiple tool head adapted, at will, to be attached to or removed from a main tool head, the counter-balancing means being operative wholly independent of the main tool spindle and not materially increasing the load carried by the drill arm. Without further analysis, the foregoing will so fully reveahthe gist of this invention that others can, by applying current knowledge, readily adapt it for various utilizations by retaining one or more-of the features that, from the standpoint of the-prior art, fairly constitute essential characterlstics of either the generic or specific aspects of this invention and, therefore, such adaptations should be, and are intended to be, comprehended within the meaning and range of equivalency of the following claims.

Having thus revealed this invention, we claim l as new and desire to secure the following combinations and-elements, or equivalents thereof, by Letters Patent of the United States:--

1. In combination with a conventional radial drilling machine having a translatable main tool head, a sleeve translatably mounted therein and a main spindle rotatably journaled in the sleeve, of a supporting frame secured to and translatable with said main tool head; an auxiliary head slidably mounted on said frame and translatable with said main spindle; a'plurality of auxiliary spindles journaled in said auxiliary head; means to rotate said auxiliary spindles from said main spindle, said frame, auxiliary head and auxiliary spindles being readily detachable from said main tool head, as a unit, to restore the machine to a conventional single spindle radial drill; and spring means carried by said frame for counterbalancing the weight of said auxiliary tool head.

2. In combination with a drilling machine having an arm; a main tool head translatable thereon and a main spindle rotatably and translatably journaled in said tool head, of a unitary supporting frame removably" secured to the lower end of said main tool head; an auxiliary head supported on said frame and connected to be translated with said spindle; and spring means carried by said frame for counter-balancing said auxiliary head.

3. In a radial drilling machine having an arm; a main tool head translatable thereon, a sleeve translatably journaled in said head and projecting from the lower end thereof and a main topl spindle rotatably journaled in said sleeve, of a supporting frame surrounding the projecting end of said sleeve and detachably secured to the lower end of said head and readily removable therefrom; an auxiliary tool head translatably mounted on said frame; a plurality of auxiliary spindles journaled in said auxiliary head; means to rotate said auxiliary spindles from said main spindle; and yielding counter-balancing means carried by said frame and acting upon said auxiliary head normally to maintain it elevated but permitting it to be depressed by the translation of said spindle.

i. In combination with a drilling machine having an arm; a main tool head translatably mounted thereon, a sleeve translatably mounted therein and a main spindle rotatably and translatably journaled in said sleeve, of an auxiliary tool head carried by said main tool head; a plurality of tool spindles journaled in said auxiliary head; means to rotate said auxiliary spindles from said main spindle; and means independent of said sleeve and carried wholly by said auxiliary tool head for counter-balancing the latter.

5. In combination with a drilling machine having an arm; a main tool head translatable thereon and a main spindle rotatably and translatably journaled in said main tool head, of a supporting member secured to said tool head; an auxiliary head slidably mounted on said supporting memher; a plurality of auxiliary spindles journaled in said auxiliary head and rotated from said main spindle; a plurality of spring devices carried by said supporting member and acting upon said auxiliary head to counter-balance the latter; and means to vary the effectiveness of said spring devices to compensate for variations in the Weight of said auxiliary head and the parts carried thereby.

6. In a machine tool, an arm; a tool head translatably mounted thereon; a rotatable and translatable main spindle journaled in said tool head; a supporting member secured to said tool head; a plurality of guides carried by said member and arranged parallel to the axis of said spindle; an auxiliary tool head slidingly supported on said guides; and springs cooperating with said guides and acting upon said auxiliary head normally to maintain it in a retracted position but permitting it to be moved therefrom by the translation of said spindle.

7. In a drilling machine having a main tool head and a main spindle rotatably and translatably journaled therein; a supporting member removably secured to said head; a plurality of rods carried [by said member; an auxiliary tool head surrounding said rods and adapted to be translated with said spindle; a plurality of auxiliary tool spindles journaled in said auxiliary head; means to rotate said auxiliary spindles from said main spindle; a coil spring surrounding each of said rods and having one end engaging said auxiliary head; and a nut threaded upon each' of said rods and engaging the other end of the Spring thereon and serving by adjustment on the rod to vary the tension of the spring, said springs serving to retract said auxiliary head.

8. In combination with a main tool head having a main spindle rotatably and translatably journaled therein, of a unitary auxiliary multiple spindle head and counter-balancing means therefor adapted to be'removably secured to said main tool head as a unit with the main spindle operatively connected to rotate auxiliary spindles journaled in said auxiliary head, said unitary structure comprising a frame; means to secure said frame to said main head; an auxiliary head translatable with the main spindle relative to said frame; and counter-balancing springs interposed between said frame and said auxiliary head and serving normally to retract said auxiliary head but permitting it to be advanced by the translation of said main spindle.

9. In combination with a drilling machine having a main tool head, a sleeve translatably mounted in said tool head and having one end projecting therefrom and a main spindle rotatably journaled in said sleeve, of an auxiliary tool head secured upon the projecting end of said sleeve and translatable therewith; a plurality of auxiliary spindles journaled in said auxiliary head; means to rotate said auxiliary spindles from said main spindle; a member surrounding said sleeve and secured to said main tool head;

rods secured to said member and having a telescoping fit with a portion of said auxiliary tool head; and counter-balance springs surrounding said rods and interposed between an abutment thereon and a portion of said auxiliary head and normally tending to elevate said auxiliary head.

10. In a drilling machine having a main tool head and a main spindle rotatably and translatably journaled therein, a supporting member scoured to said head; 9, plurality of guide members projecting from said supporting member; an auxiliary tool head slidingly mounted on said guide members and provided with a plurality of auxiliary spindles; means to rotate said auxiliary spindles from said main spindle; a connection between said auxiliary tool head and said main spindle to translate the former by the latter; and spring means between said guide members and said auxiliary head for yieldingly supporting said auxiliaryhead on said supporting member.

11. In a drilling machine having a main tool head and a main spindle rotatably and translatably journaled therein, a supporting member secured to said head; a plurality of rods carried by said member; an auxiliary tool head having tubular portions surrounding said rods and adapted to be translated thereon by the translation of said spindle; and coiled springs surrounding said rods within said tubular portions and having one end engaging an abutment on said rod and the other end engaging an abutment provided by said auxiliary head thereby normally to maintain said auxiliary head retracted.

12. In combination with a drilling machine having a main tool head, a sleeve translatably mounted in said tool head, a main spindle rotatably journaled in said sleeve, of an auxiliary tool head carried by the main tool head and translatable with said sleeve; a plurality of auxiliary spindles journaled in said auxiliary head; means to rotate said auxiliary spindles from said main spindle; a member secured to said main tool head and provided with portions having a auxiliary tool head being bodily removable from the main tool head with said supportingframe;

a plurality of auxiliary spindles journaled in said auxiliary tool head; means to rotate said auxiliary spindles from said main spindle; and spring means carried by said frame and bodily removable therewith for counterbalancing said auxiliary tool head.

AWRENCE LEE SCHAUER. JESSE B. KINCAID. 

